1. Field of the Invention
The present invention relates to an optical disc device, and more particularly, to an optical disc device that reduces influence of an electric wave coming from outside of the optical disc device and an electric wave originating from inside the optical disc device.
2. Description of the Related Art
In situations where maintenance is not performed, electric devices may be subject to functional decline, malfunction, shutoff, and recorded data may be lost due to the influence of eradiated electromagnetic waves coming from other nearby devices. Especially, an electromagnetic wave eradiated from a radio device may have an influence, such as resonance, on other electronic devices. As for countermeasures against the radio-frequency interference and immunity, various research has been done.
For example, concerning electronic devices having mounted thereto a portable recording medium, there is suggested an electronic device which is configured such that a metal plate, etc. of the insertion surface of a portable recording medium does not resonate with an electric wave generated outside of the device (for example, Jpn. Pat. Appln. Laid-Open Publication No. 2001-67851).
Furthermore, there is suggested an image forming device in which an opening provided at a metal housing to make a laser beam go through operates as a slot antenna. A conductive member is arranged between both sides in the longitudinal direction of the opening provided at the metal housing to make a laser beam go through so as not to raise the slot antenna eradiation phenomenon in a frequency band in which two times the length of the opening in the longitudinal direction is set to one wavelength (for example, Jpn. Pat. Appln. Laid-Open Publication No. 2003-262818).
According to the conventional technique, the resonance point caused by an electric wave coming from outside and an internal electric wave is shifted by attaching a conductive member to a front surface opening of a device using a portable recording medium or an image forming device such that the longitudinal length is divided in half.
However, according to above-described conventional suggestion, it is assumed that the frequency of an electric wave coming from outside is 1.5 GHz, and noise standard up to 1 GHz is supposed. On the other hand, electric waves eradiated from various electronic devices are not definitively of a single kind.
Accordingly, even though a conductive member is attached to a single position to shift the resonance point, as in the conventional technique, a problem arises because the influence of the interference cannot be completely removed.